Evinrude 25 hp problems

HI GOT A 25 HP EVINRUDE FROM D

HI GOT A 25 HP EVINRUDE FROM DAD. THIS MOTOR SAT FOR 2 YEARS IN GARAGE. LAYING ON ITS SIDE .DON'T KNOW YEAR BUT IT IS FROM MID 80'S . TAGS ARE GONE. THIS MOTOR RUNS OK BUT THE TELL TAIL STOPS SPITTING WATER SOMETIMES AND ENGINE STARTS TO COUGH AND BACKFIRE. BUT AT FULL THROTTLE IT FLIES

"u have an excellent engine.al

"u have an excellent engine.all the mid 80's engines,are my favorites,...gas hogs for sure,...but great old dawgs.....ok,....lets get her up tip top shape...if u r the mechanic type,
You said it runs ok,but for future reference,if u have the tools,ck spark,and,compression,and proceed w/the following:
clean/rebuild the carb--w/new kit
install new spark plugs-champion,QL77JC4-GAP-.030
chg lower unit oil
de-carb the eng
inst a new water pump kit
** get you, a FACTORY service manual,u will have most of the info u need,and the rest,u can get from us here."

thanks this engine also calls

thanks this engine also calls for 100/1 fuel/oil mix is that right

"absolutely not,...50/1--1 pin

"absolutely not,...50/1--1 pint to 6 gal gas..that was a huge mistake..bulletin after bulletin about that.."

no that was a mistake.........

no that was a mistake...........you should mark it out if it is on the motor in any place.


it should be 50:1..........i read about this on another thread......so no matter whtat is on the eng it is 50:1 and needs to be water cooled oil ---- no chainsaw nor weedeater oil

"and,i am very glad u ask,...i

"and,i am very glad u ask,...i wonder,if the other owners have run that eng that way...in my opinion,.....that was way too lean on any of the 2 stokes,but,..i am not an engineer of 2 strokes ."

"i had an old friend,last year

"i had an old friend,last year,try to buy a johnson 25,none avail,so,dreadfully,he had to buy a yammi 25..well,that yammi,came w a sticker on the sd that proudly displayed...100/1---
after 5pm,3 beers, and alot of talking i think i convinced him to do away w/that,sticker,and mix 50/1."

The 100:1 mix has a little les

The 100:1 mix has a little less smoke but its not worth the risk of engine damage over time.

50:1 is the only way to go

"I don't want to dispute t

"I don't want to dispute the 50:1 mix since that is what is required, but isn't that more to do with the type of oil used than the engine?

In the 60ties there was no 50:1 oil and we used 25:1 mineral oil SAE 30. Dreadful dirty but worked.
Then they invented the low ash oil yet you needed to use even more of it since some of the volume of oil was some form of detergent additive.
Then they came up with 2stroke oil for air cooled and a different for water cooled. Then the race begun to see who could formulate the oil that needed less volume per litre of petrol and so the mixture became leaner and leaner. The less oil you need the dearer it is.

We have today 30:1 / 40:1 / 50:1 and 100:1
2stroke oil.
All are different formula. each one cna be used successfuly in the same motor.

If for example you run out of your 50:1 oil and can only find one that read 40:1, you should mix 40:1 and not 50:1.
Similarly if you want to venture in using a special oil formulated for 100:1, that is how you mix it. I would probably stay away from it but that is me."

"2-stroke oil and mixture are

"2-stroke oil and mixture are mainly a lot of compromises.
The older engines with bushings an not needle bearings needed 4% oil-mix in general, the newer ones 2% mix was/is sufficient. Then with even better alloys and materials some chose to go for 1% as recommendation. In general most modern 2-strokes (with needle bearings) will run on 1% without problems, however they will not last long NOT running on 1%. Use Your Evinrude/Johnson daily and You may run on 1%, use it once a week or even in longer intervals it will probably corrode to pieces and suffer premature wear. Not from the running itself, but from the excessive wear at each start when there is no oil left from last running.! The same goes for Yummies.
Low ash, no-ash, no smoke and so on is another part.
The best, for the engine, would be that the oil is no smoking. That on the other hand means it is not burning and the oil goes straight back into the sea unburned! The more smoke, the less oil goes out, but in general the more carbon build-up You will have in combustion chambers, exhaust systems etc.Technically a bio degradable oil that does not burn and is concentrated on lubrication only might be the best, but even the most expensive to produce. No smoke, less carbon, environmental friendly. On the other end You have the smoking ones that burns the most. These oils are often mixed with 'solutions' to make them burn (low flaming point), leaves no oil-trace, but on the other hand has less lubricating abilities pr unit oil. Pick Your choice what You want, but You can not have it all in one bottle.
(I leave the hi-tech injected engines out of the discussion.)"

"Interesting discussion...I do

"Interesting discussion...I don't think the traditional two stroke will be around much longer...the push to the 100 to 1 ratio certainly had something to do with exhaust emissions...Two engines which come to mind are the British Seagull which I seem to remember, required a 10 to 1 mixture. The other engine is the Merc/Yamaha 2+2 with the bottom cylinders running on almost zero fuel/oil at under 1800 RPM....I don't know how much oil those bottom cylinders ran on, but those motors idled smoothly all day without lubrication problems. The oil required for lubrication certainly has to be related to load and throttle position( that's the theory behind the VRO concept"

"I agree on the above, however

"I agree on the above, however you only mention changes in the bearings and not in oil technology.
I have an old Homelite chainsaw from the 60ties that reads 16:1 mixture. That is what was required with SAE30 mineral oil. Today I run that engine on 30:1, and could probably go 40:1. It is the same engine yet different oil. If I only had mineral oil for the mix I would have to go back to 16:1
My 25HP (96) Evinrude runs on 50:1 outboard oil, yet if I run out of that, I would have to mix 25:1 SAE 30."

"thanks for all the help i am

"thanks for all the help i am going to check the 25 out this weekend and will get back to you
its been to cold here to do anything this is illinois you know PS. i still don't know the year of this motor i found some # on the CARB 598084mx03cm , on the POWER HEAD 326713a, and on the FREEZE PLUG dq5tecure0685933 if you can determine the year i would love it THANKS ALOT MIKE THE ID TAG IS CLEAN ON THE MOUNT NO #,S"

i finally found the year of th

i finally found the year of this motor it is a 1987 evinrude e25tecu